Caulking gun

ABSTRACT

A caulking gun having a push rod-formed by two interlocking chains. The caulking gun comprises a barrel having an open framework for receiving and cradling a caulk cartridge. A self-contained drive mechanism is provided to forwardly advance a chain arrangement comprising two separately coiled chains, each composed of a series of individual links connected in pivotable fashion one to another. The shape of the individual links of the two chains enables them to be interlocked as one parallel chain, forming a push-rod to compress the caulk cartridge, for extrusion of material contained therein. The coiled chains enable the chain arrangement to bend 180 degrees, so that the overall caulking gun length is reduced. The caulking gun is preferably made entirely from plastic. A caulk cartridge is retained within the barrel of the device by a pair of locking clips which may be closed by a sliding ring mechanism.

FIELD OF THE INVENTION

The present invention relates to dispensing devices and moreparticularly to an open-framed cartridge caulking gun having a push-rodformed by two interlocking chains.

BACKGROUND OF THE INVENTION

Caulk is a waterproofing material used by building contractors andhomeowners for sealing windows, doors and bathtubs.

Caulk is most conveniently dispensed and applied using caulking guns, towhich are fitted a plastic or cardboard tube containing caulk.

Two main types of caulking guns are known. The first is the bulkdispensing gun, which is a complete unit containing a closed cylindricalchamber with nozzle and actuating means. The second is the open framedcartridge gun, in which the gun itself and a disposable cartridgecontaining caulk comprise separate elements.

The open-framed cartridge gun typically comprises a cradle to receive acartridge containing caulk, one end of the cartridge having a dispensingnozzle. A piston is provided within the cartridge. Caulk is dispensed byexerting pressure on a trigger of a pistol-grip mechanism, whichactuates a push rod having a thrust disk at its front end. Pressureexerted by the thrust disk against the caulk cartridge piston forcescaulking material out of the cartridge nozzle.

Many variations of the open-framed cartridge gun have been described inthe art. In all of these, the push rod is at least as long as thecartridge, plus the distance the push rod must travel through thepistol-grip mechanism in order to be able to urge the thrust disk alongthe entire length of the cartridge. In addition, a small segment of thepush rod must remain exposed after the cartridge has been depleted sothat the exposed segment of the push rod can be grasped by hand andretracted to the starting position. The total length is furtherincreased by the nozzle of the cartridge when full, resulting in arelatively long caulking gun. Such a device is awkward to handle andcannot easily fit into tight spaces such as cupboards, closets, behinddoors etc.

In existing open-framed cartridge guns the cartridge is inserted byfirst retracting the push rod, then manually manipulating the cartridgeinto place. The cartridge is released by retracting the push rod whilesimultaneously pressing a release lever or button. These manipulationsare awkward and time-consuming.

Therefore, it would be desirable to provide a cartridge caulking gunwhich is shorter and easier to manipulate than the prior art devices,and in which loading and removal of cartridges is simplified.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to overcome thedisadvantages of the prior art and provide a relatively short caulkinggun, which is easy to manipulate.

In accordance with a preferred embodiment of the present invention,there is provided a caulking gun formed entirely of plastic, whicheliminates the problems of rusting and general wear and tear associatedwith prior art devices. The caulking gun comprises a barrel having anopen framework for receiving and cradling a caulk cartridge providedwith an extrusion nozzle at one end. A drive mechanism is provided toforwardly advance a chain arrangement comprising two separately coiledchains, each composed of a series of individual hollow links connectedin pivotable fashion one to another. The shape of the individual chainlinks of the two chains enable them to be interlocked as one parallelchain, forming a push-rod to compress the caulk cartridge piston, toempty it of material. The coiled chains enable the chain arrangement tobend 180 degrees, so that the overall caulking gun length is reduced byeliminating the backward protruding rod of the standard device.

According to a preferred embodiment, there is provided a caulking guncomprising an elongated body, a pair of chains situated within theelongated body in coiled fashion, the chains being fixedly interlockedone to another at a front end thereof, a coiled portion of the chainsbeing reversibly interlockable one to another to form a push-rod whenextended, a disk-shaped element attached to the push-rod, aself-contained driving mechanism for graduated extension of the coiledportion of the pair of chains in parallel interlocked fashion, formingthe push-rod, and a release mechanism for restoring the pair of parallelchains to their fully retracted, coiled position, such that by repeatedactivation of the driving mechanism, the coiled chains are brought intointerlocking contact one with the other, increasing the length of thepush-rod, thereby carrying the disk element forward against a caulkcartridge inserted within the elongated body, causing extrusion ofmaterial contained in the cartridge.

A feature of the present invention is that the push-rod of the caulkinggun is formed by interlocking of two parallel chains.

An advantage of the present invention is that the caulking gun isshorter than conventional devices and therefore easier to manipulate.

A further advantage of the present invention is that loading and removalof the cartridge of the caulking gun is rapid and simple.

A further advantage of the present invention is that the device isextremely lightweight.

A further advantage of the present invention is that the device requiresless storage space than prior art devices.

A further advantage of the present invention is that the device isformed entirely of plastic, therefore no rusting occurs.

A further advantage of the present invention is that it does not includea protruding push-rod, and is therefore safer to use than conventionaldevices.

A further advantage of the present invention is that the operatingmechanism is closed, eliminating problems of exposure to dirt and otherharmful matter.

A further advantage of the present invention is that the device isoperable with one hand.

A further advantage of the present invention is that a caulkingcartridge may be quickly inserted and removed from the device byoperation of a slidable locking mechanism.

Additional features and advantages of the invention will become apparentfrom the following drawings and description.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention with regard to theembodiments thereof, reference is made to the accompanying drawings, inwhich like numerals designate corresponding sections or elementsthroughout, and in which:

FIG. 1 is a side view of a caulking gun constructed and operated inaccordance with the principles of the present invention;

FIG. 2 a is a perspective view of the caulking gun of FIG. 1;

FIG. 2 b is a perspective view of an alternative embodiment of thecaulking gun of FIG. 1;

FIG. 3 is an exploded view of the caulking gun;

FIG. 4 is a cross-sectional side view of the caulking gun; and

FIG. 5 is a cross-sectional top view of the caulking gun.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference is now made to FIGS. 1, 2 a and 2 b, which illustrate thecaulking gun 10 of the present invention.

Caulking gun 10 comprises a barrel 12, having a rear edge 13, a handle14 extending essentially perpendicular to barrel 12, and a trigger 16positioned within handle 14 for operating a drive mechanism 26 (shown inFIGS. 3-5). A removable closure 19 is attached to wall 13.

Caulking gun 10 is formed entirely of plastic such asfiberglass-reinforced polypropylene, fiberglass-reinforced polycarbonateor fiberglass-reinforced nylon. Use of plastic eliminates the problemsof rusting and general wear and tear associated with prior art devices.

Barrel 12 comprises a slightly flattened tube having an open frameworkfor receiving and cradling a caulk cartridge or canister (not shown)provided with an extrusion nozzle at one end.

The forward end of barrel 12 is provided with an open end 18 throughwhich the nozzle of the caulk cartridge is able to protrude. A pair ofL-shaped locking clips 20 are pivotally mounted one on either side ofopen end 18, such that when clips 20 are in the locked position, arecess 24 is formed between flange 21 of clip 20 and an internalprotrusion 22, situated perpendicular to the axis of barrel 12.

With clips 20 in the open position, the caulk cartridge (not shown) isinserted into open end 18 with extrusion nozzle directed outwards, untilits rim contacts internal protrusion 22. Clip 20 is then closed suchthat the cartridge rim is firmly held in position in barrel 12 withinrecess 24.

In an alternative embodiment, shown in FIG. 2 b, a contoured ring 23 ispositioned around open end 18 of barrel 12, enclosing clips 20 toprevent accidental opening of clips 20. Ring 23 is fixed in position byengaging pin 25, which may be released to enable ring 23 to be slidinglydisplaced away from the direction of open end 18 (see arrow “A”),thereby releasing clips 20. This enables a caulk cartridge (not shown)to be rapidly loaded into and removed from barrel 12.

Caulking gun 10 also includes a drive mechanism 26 and release mechanism27, described in detail below, which are situated within barrel 12 andactivated by trigger 16 and release button 17, respectively. Trigger 16and release button 17 are both operable with the same hand, such thatupon completion of caulk extrusion, release button 17 may be depressedto release residual pressure within the cartridge, thereby preventingdripping of excess caulk.

Handle 14 is an open frame comprising a horizontal lower surface 32attached to a substantially perpendicular front-facing surface 34, whichconnects lower surface 32 to barrel 12. Trigger 16 is positioned withinthe hollow rear section 36 of handle 14. Rear section 36 A plurality ofshort, raised, strips 38 are formed along the length of sides 36 toenable a non-slip pistol grip.

Referring now to FIGS. 3 to 5, the drive mechanism 26 and releasemechanism 27 are shown.

Rear surface 37 of handle 14 extends upwards into barrel 12, forming anedge 37 a. Drive mechanism 26 is positioned forward of edge 37 a andrelease mechanism 27 is pivotally attached to a flange 63 extendingbackwards from edge 37 a.

Drive mechanism 26 comprises a thrust disk 28 positioned at the forwardend of a chain arrangement 30, a biasing spring 56 positioned over chainarrangement against a jam plate 58, seated in compartment 59. Jam plate58 is formed with a window 60 through which chain 30 passes. Drivemechanism 26 is actuated by trigger 16, formed with a tapering lower endand a push tab 70 at its upper end.

Chain arrangement 30 comprises two separate chains 30 a, 30 b, eachcomposed of a series of individual hollow links 40 connected inpivotable fashion one to another. As seen in FIG. 5, each link 40 a ofchain 30 a is provided with a tab 42 and a notch 44, insertable within acomplementary notch 44 formed on each link 40 b of parallel chain 30 b.Adjacent links 40 are each pivotable about pin 46, which enables eachchain 30 a, 30 b of chain arrangement 30 to bend 180 degrees, as shownin FIG. 3.

Barrel 12 is further provided with two parallel elongated channels 48 a,48 b (FIG. 5), which run adjacent to the inner wall of barrel 12, eachhaving a width sufficient to enable seating of links 40 of a respectiveone of chains 30 a, 30 b therewithin. Channels 48 a, 48 b terminate atinternal protrusion 22, described above with reference to FIGS. 2 a and2 b.

The end of barrel 12 towards which trigger 16 is situated is providedwith a pair of circular guides 50 a, 50 b around which pass links 40 ofchains 30 a and 30 b respectively.

Guides 50 a and 50 b are spaced at a suitable distance one from theother such that when chains 30 a, 30 b pass around guides 50 a, 50 brespectively, the two chains 30 a, 30 b are forced into contact one withthe other in the region between the two guides 50 a, 50 b.

Links 40 of chain 30 a are each formed with a side protrusion 42,extending towards parallel chain 30 a, and insertable within acomplementary recess 4s4 formed on the side surface of each link 40 ofchain 30 b facing chain 30 a, such that by forcing the chains intocontact, they become firmly interlocked as one.

This firm interlock between chains 30 a, 30 b, forms a solid, inflexiblerod which serves as a push-rod 80 for driving thrust disk 28 forward.

In operation, when trigger 16 is depressed in the direction of rearsection 36 of handle 14, push tab 70 of trigger 16 is pushed forwardagainst a lower edge of jam plate 58, causing jam plate 58 to slantbackwards from an axis perpendicular to that of chain 30, and to pivotwithin channel 64. Due to the inclined orientation of jam plate 58 onchain 30, links 40 of chain 30 become engaged with an edge of window 60.Thus, as jam plate 58 moves, chain 30 moves together with it, advancingin a forward direction, against the action of spring 56. Upon release oftrigger 16, jam plate 58 returns to a vertical orientation by the actionof spring 56, releasing chain 30. Jam plate 58 returns to its originalposition while chain 30 remains in the position to which it has beenadvanced by operation of trigger 16.

Once the caulking cartridge has been used, whether it has been emptiedor if it is to be stored for re-usage, it may be removed easily fromcaulking gun 10 by releasing locking clips 20.

Release mechanism 27 comprises a locking plate 62, pivotally attached atits upper end 72 to flange 63. Locking plate 62 is formed with a window74 and is positioned so as to slant backwards from attachment point atupper end 72. Chain 30 is therefore held firmly by the edges of window74 of locking plate 62, preventing chain 30 from retracting andreturning to its original position after release of trigger 16. Uponexertion of pressure on release button 17, the lower end of lockingplate 62 of release mechanism 27 moves forwards, causing locking plate62 to straighten vertically from the inclined angle, resulting indisengagement of chain 30. Chain 30 may then be manually retracted byexertion of pressure upon thrust disk 28.

The entire drive mechanism 26 is enclosed within a suitably shaped,removable, snap-on covering 19 which provides protection from exposureto dust and other airborne particles, oil, water etc. which coulddecrease the efficiency of the mechanism.

The present invention therefore provides a caulking gun 10 in which thepush-rod 80 is formed by two retractable, interlocking chains 30 a-b,enabling the gun to be designed with significantly reduced length incomparison with standard caulking guns, based on use of a self-containeddriving mechanism. The resulting gun is simple to use and is easy tomanipulate in small, confined spaces. Less storage space is alsorequired. The absence of a protruding push-rod renders the caulking gun10 safer to use.

The plastic composition of caulking gun 10 eliminates the problem ofrusting which is common in conventional caulking guns and provides andextremely lightweight device. Furthermore, plastic is less susceptibleto general wear and tear which occur as a result of repeated use.

Having described the invention with regard to certain specificembodiments thereof, it is to be understood that the description is notmeant as a limitation, since further modifications will now suggestthemselves to those skilled in the art, and it is intended to cover suchmodifications as fall within the scope of the appended claims.

1. A caulking gun comprising: an elongated body having an open frontend; a pair of chains situated within said elongated body in coiledfashion, said chains being fixedly interlocked one to another at a frontend thereof, a coiled portion of said chains being reversiblyinterlockable one to another to form a push-rod when extended; adisk-shaped element attached to said front end of said push-rod; aself-contained driving mechanism for graduated extension of said coiledportion of said pair of chains in parallel interlocked fashion, formingsaid push-rod; and a release mechanism for restoring said pair ofparallel chains to their fully retracted, coiled position, such that byrepeated actuation of said driving mechanism, said coiled chains arebrought into interlocking contact one with the other, increasing thelength of said push-rod, thereby carrying said disk element forwardagainst a caulk cartridge inserted within said elongated body, causingextrusion of material contained within said cartridge.
 2. The caulkinggun of claim 1 further comprising a handle downwardly extending fromsaid body.
 3. The caulking gun of claim 2 wherein said driving mechanismcomprises a trigger positioned within said handle, said trigger beingprovided with a push tab at its upper edge.
 4. The caulking gun of claim3 wherein said driving mechanism further comprises: a biasing spring;and a vertically-oriented driving jam plate formed with a window forinsertion therethrough of said parallel chains, such that upon exertionof pressure on said trigger, said push tab causes said driving jam plateto become inclined at an angle, engaging said interlocked parallelchains within said window of said jam plate, and forwardly displacingsaid push-rod against the action of said biasing spring.
 5. The caulkinggun of claim 4 wherein said release mechanism comprises: a backwardlyinclined locking plate provided with a hole for insertion therethroughof said parallel chains; and a release button, such that upon release ofsaid trigger, said jam plate returns to a vertical position by theaction of said biasing spring, releasing said interlocked parallelchains, and such that exertion of pressure on said release button causessaid inclined locking plate to be moved to a vertical position, therebyreleasing engagement with said parallel chains and enabling saidinterlocked parallel chains to be returned to their original position byexerting pressure on said disk-shaped element.
 6. The caulking gun ofclaim 5 wherein exertion of pressure on said release button enablesrelease of residual pressure within the cartridge, thereby preventingdripping of excess caulk.
 7. The caulking gun of claim 1 wherein saidelongated body is provided with a pair of oppositely-situated channelsrunning parallel to the inner side walls of said elongated body, suchthat each of said pair of parallel chains is retained within one of saidparallel channels.
 8. The caulking gun of claim 1 wherein a pair ofguide wheels are oppositely positioned rearward of said drivingmechanism, adjacent to said pair of chains and separated by a distancecorresponding to the width of said interlocked parallel chains, suchthat said pair of guide wheels force said pair of parallel chains intolinked contact in the region between two said circular elements.
 9. Thecaulking gun of claim 1 wherein each of said pair of chains comprises aplurality of pivotally connected box-shaped links.
 10. The caulking gunof claim 9 wherein each of said links is provided with a protruding tabon an inwardly-facing vertical face and a recessed notch formed on anoppositely situated vertical face, such that said tab of one of saidlinks of a first of said parallel chains is insertable within said notchof an adjacent of said links of said second parallel chains.
 11. Thecaulking gun of claim 10 wherein said links are hollow.
 12. The caulkinggun of claim 1, formed entirely of plastic.
 13. The caulking gun ofclaim 1 wherein said elongated body comprises a slightly flattened tubehaving an open framework for receiving therein said caulk cartridge. 14.The caulking gun of claim 1 wherein said elongated body is provided withat least a pair of locking clips oppositely mounted on either side ofsaid open end of said elongated body for fixedly retaining a front rimof said caulk cartridge.
 15. The caulking gun of claim 14 wherein saidlocking clips are pivotally mounted.
 16. The caulking gun of claim 15further provided with a contoured disc slidingly positioned over saidopen front end of said elongated body so as to releasably engage saidlocking clips.
 17. The caulking gun of claim 2 wherein said handle is anopen-frame.
 18. The caulking gun of claim 17 wherein said handle isprovided with a plurality of raised non-slip strips along an outer rearside.
 19. The caulking gun of claim 1, having significantly reducedlength.
 20. A method for extruding caulk contained within a caulkinggun, comprising the steps of: providing a caulking gun comprising anelongated body having an open front end, a pair of chains situatedwithin said elongated body in coiled fashion, said chains being fixedlyinterlocked one to another at a front end thereof, a coiled portion ofsaid chains being reversibly interlockable one to another to form apush-rod when extended, a disk-shaped element attached to said front endof said push-rod; a driving mechanism for graduated extension of saidcoiled portion of said pair of chains in parallel interlocked fashion,forming said push-rod, and a release mechanism for restoring said pairof parallel chains to their fully retracted, coiled position; insertinga caulk cartridge provided with an extrusion nozzle at one end withinsaid elongated body; and repeatedly actuating said driving mechanism,such that said coiled chains are brought into interlocking contact onewith the other, increasing the length of said push-rod, thereby carryingsaid disk element forward against the caulk cartridge inserted withinsaid elongated body, causing extrusion of the caulk contained within thecartridge from said extrusion nozzle.
 21. (canceled)
 22. (canceled)